Codel does well.

Top Line: The debate over adjuvant versus salvage radiation for the better behaving oligo- (aka 1p/19q co-deleted) gliomas promises to remain in full swing for the foreseeable future.

The Study: While it’s a good problem to have, outcomes with any ongoing trials such as CODEL won’t have enough events to report for years to come. And with the molecular renaissance upheaving all our old classifications, it’s hard to know how to apply the data in our landmark trials from the days of yore. This multi-institutional retrospective look at 186 patients treated with radiation for co-deleted tumors at one of four large academic centers aims to interpret the impact of the timing of radiation (i.e., adjuvant versus salvage). Two-thirds received adjuvant radiation and virtually none were low risk (i.e, <40 years with gross total resection). The remaining third of patients received salvage radiation at a median of 5 years from initial surgery, and multivariate analysis did not reveal a difference in survival. Importantly, nearly half of those receiving salvage had already received chemo alone, which did nothing to delay radiation and was even associated with a shorter time to progression after radiation. FInally, two-thirds of patients received ≥58 Gy, which had no bearing on disease outcomes but resulted in a 15% rate of radionecrosis versus 0% with lower doses.

TBL: This retrospective look at exclusively 1p/19q co-deleted oilgos suggests post-resection observation with salvage chemoradiation to lower radiation doses typically used for low-grade glioma is a good strategy. | Lin, J Neurooncol 2019